Who's That Girl?
by EquinoxCroll
Summary: Head Girl, Lily Evans is used to the odd things that happen at Hogwarts. Very little fazes her – especially when it comes to the Head Boy and his gang. But when she discovers there's a new girl at Hogwarts, who has entranced all her friends, she's determined, along with James, to find out her identity. After all, since when has Hogwarts accepted American Exchange Students.
1. Chapter 1

"It was here somewhere," Lily Evans muttered, in an exasperated tone. She was searching through her school bag, pulling all her things out and throwing them onto the floor of the common room.

"What's that?" asked Mary, looking up from the Defence essay to which she was making last minutes corrections.

"My blue folder. I need to find the notes from the last prefects' meeting to show to Professor McGon – UGHH!" She pulled a face as she looked at her hand, now covered with something gooey. "Merlin, I'd forgotten about that bag of treacle toffee. Must have melted in this weather."

"You're very forgetful all of a sudden," Sirius remarked casually as he grinned at Mary. "Not getting distracted by the Head Boy, are you?"

Lily turned around and resisting the urge to poke out her tongue settled for giving Sirius one of her 'looks'. (She'd practised them since her third year, imitating Petunia). "I haven't seen Potter since Herbology," she replied scornfully.

"Hey, Evans, you dropped this in ... uh ... the library," called James as he walked through the door. He was carrying something in his hand – her journal.

"Not since Herbology, eh, Evans?" Sirius cooed, adding to Mary, "Blushing is not a good look for your mate, is it?"

Giggling, Mary agreed, "Why don't you just admit that something is going on with you two?"

"Because it's NOT!" shouted both James and Lily simultaneously.

"We have just decided that as we have to work together, it's best for the school if we don't argue," Lily explained coldly. Taking the book from James and determinedly not looking him in the eye, she began to pack her things away.

James bent down and picked up a magazine that she'd tossed on the floor. He was about to hand it to her, but catching her sly wink, he thought better of it, instead stuffing the magazine under his robes. He cleared his throat. "Anything interesting in the paper, Padfoot?"

Sirius yawned. "Not really. Someone won a load of Galleons betting on the Arrows' game. The Goblins aren't happy and want an investigation, but then they're never happy." He chucked _The Prophet_ on the table. "Wish I could win some money," he grumbled. "I hate being skint."

"What happened to the inheritance from your Uncle Alphard?" Mary asked, her eyebrows raised in amazement. "He left you masses!"

Sirius scowled and looked across at James. "Well, after I bought the motorbike, James' mum and dad thought I was being irresponsible, so they sort of stopped me spending anymore."

"Am I hearing right?" Lily said and started laughing. "Since when has anyone been able to stop you doing what you want?"

James started grinning and, vaulting over the back of the sofa, landed alongside Sirius. "My Ma and Pa are very good at playing the guilt card. They persuaded Padfoot to open a bank account."

Mary and Lily collapsed with mirth. "Sirius Black, responsible. Oh sweet Merlin, pinch me, I must be dreaming!" Mary exclaimed.

"You won't be laughing when I have my own pad," Sirius declared airily. "My house-warming party will be legendary." He smirked. "So watch out, 'cause I might not invite you if you keep taking the piss."

"Oh, Sirius," Lily sighed. "Face it, you need girls at your party and as Mary and I are the only witches you haven't tried to pull ..."

"It's quite insulting, actually," Mary said idly, not sounding in the slightest bit offended. "I'm starting to think there must be something wrong with me."

"Mary, my sweet," Sirius said as he stood up and stretched. "The only thing wrong with you is that I'd get hexed to pieces by one of my mates if I went anywhere near you."

"Not to mention her sister," Lily put in. "Have you made up with Martha yet?"

"Nope," Sirius replied. "She knows where I am. Meanwhile I shall console myself with the new girl."

Lily frowned. "What new girl?"

"Uh, American, I think," Sirius said and started to smile. "Bloody gorgeous. I bumped into her coming out of Professor Fawcett's classroom. She said she was an exchange student."

"Since when has Professor Dumbledore -" began Lily, but then shook her head. With the prospect of war looming, she knew the Headmaster was keen to extend the hand of friendship to other countries and especially other schools. "What's her name?"

"Jill," Sirius replied dreamily, "Jill Munroe. Beautiful big blue eyes – or maybe they were green? Wonderful long blonde hair that sort of flicks back, and wow, what a pair of ... lips."

"Professor Fawcett's got an American wife," Lily said, ignoring Sirius' insinuation and mime that obviously referred to the new girl's chest. "Perhaps it's his daughter."

Sirius snorted. "Not looking like that. Fawcett's an ugly bugger. Anyway, I'm off. See you at lunch."

"Where are you going?" Mary asked, pulling on his arm. "Martha will be back soon. Perhaps you could ..."

"Nope," Sirius replied. "I said I'd meet Remus and Peter in the library. You coming, Prongs?"

"Uh..." James had started reading _The Prophet_. Engrossed in the article, he shook his head. "Nah, you go. I'll see you later."

As Lily watched Sirius leave, she frowned. Mary had picked up her homework again, and James was still reading the newspaper, but she wanted to talk.

"Have either of you met this new girl? Jill Whatsit?" she asked.

James shook his head, but Mary nodded. "She was in my Muggle Studies class. She's pretty amazing, actually, and told us all about Muggles in America."

"So where's she staying?"

"In with us, of course," Mary said as if that explained everything. "Lily, we talked about this last week."

"Did we?"

Mary stood up and smirked. "I think I'll join the boys in the library. Sirius is right about you. You're definitely distracted by something ... or someone," she said, giving James a knowing glance.

Lily scowled at her but said nothing. She looked at her hand; it still felt sticky from the toffee. "Perhaps they're right," she said to James. "I am becoming forgetful."

"Am I too distracting?" James replied.

"Definitely," she whispered.

"Same time tonight?" he mumbled.

"Mmm, should be okay, but ..." She stopped speaking as Martha entered the common room, and shifted away from James. "Not the usual place. Check the magazine, page seventeen, okay?"

James always liked Lily's magazines. For a start, she got her mum to send them to her so they were Muggle magazines. Then there were always the quizzes. Under the cover of the desk, whilst Professor Fawcett was droning on and on about the advantage of non-verbal spells, which James had mastered in his fifth year, he started reading the 'Which Charlie's Angel Are You?' quiz. He had no idea what a Charlie's Angel was, but it turned out he was Kelly Garret; beautiful, reckless and a crack shot. Then he started reading a letter on the problem page about a girl who wasn't sure if she should go steady with her boyfriend. He frowned slightly, wondering if Lily had written it.

He understood her reservations. After so many years of leading separate, but parallel lives, that only touched when she was shouting at him, Lily wanted to take things slowly and without the 'help' of their friends. For his part, he knew Sirius would be unbearable as soon as he found out, but then his mate was unbearable anyway, so James didn't see what would change.

"POTTER!" roared Professor Fawcett, the wart above his lip quivering. "I should not have to tell you _every single time_ to pay attention!"

"Uh ... sorry, sir." James tried to stuff the magazine into his bag, but the professor was too quick for him and snatched it out of his grasp.

"Mindless rubbish!" the professor yelled. "Filling your brain with stupid Muggle nonsense."

"Yes, sir, sorry sir," James babbled. "Uh, could I have it back? I promise I'll put it away."

"NO!" Fawcett was scowling at the magazine as he leafed through the pages.

Briefly, James saw Lily's handwriting on page seventeen and caught the word 'Slughorn'. He sat back, not needing to argue anymore and grinned at his friends as the professor walked off.

"Why were you reading a girls' magazine?" Peter whispered.

"Fit birds," James replied. "Why else?"

Remus raised one eyebrow, not commenting, but James saw him nudge the other two and heard the three of them stifling snorts.

_Bloody hell, Lily, _he thought. _Can't we just get this over with?_

To escape the witterings of Sirius, who was still, along with Remus and Peter, going on about the new girl, James decided to skip down to Slughorn's storeroom early. He'd met Lily there once before and was surprised she'd suggested there again because it wasn't the most conducive of places to meet for a snog. The Charms classroom was much better; Slug's storeroom smelt funny and was far too close to the Slytherin common room for comfort.

Entering the dungeons, he gripped his wand tight, and kicked himself for not bringing the Cloak, but Lily had no idea of its existence and he didn't want to waste time with explanations tonight.

He heard a noise and ducked into an alcove just in time to see Avery and Regulus on patrol.

"Have you seen the way she walks?" he heard Avery say. "She sort of glides."

"You're lucky she's in your year," Regulus complained. "And now she's staying with those Gryffindor girls, I doubt any of us will get a look in."

"I'll give her something to look at," Avery replied, sniggering. "Once she cops an eyeful of me, she is not going to want to leave me alone."

"What are you going to do – drug her?"

"Oi! I don't need Amortentia to pull –"

"You haven't been out with anyone for months!"

"I'm choosy."

James stifled a snort. He was grinning to himself and quite forgetting that these were two of his enemies talking. Regulus sounded uncannily like Sirius at times. Then he heard their footsteps falter.

"That's not a bad idea, though," Avery said. "At least it would stop your bloody brother – or Potter - getting their paws on her."

_Shit, if they come back this way, then they'll see me._ James held his breath and strained his ears as he tried to hear Avery's deliberations.

"Slughorn will know," Regulus replied. "He was moaning about ingredients going missing today. Asked me if I knew anything about it." He paused, and peeping out, James saw Regulus smirk. "I didn't tell him we'd nicked that Euphoria Potion. He still thinks we were happy after that Quidditch win."

To his relief, James heard Avery mutter in agreement and then the two Slytherins walked back to their common room. As it was a Friday night, he was fairly sure they'd slack off and not patrol again. Now all he had to do was edge across to the storeroom and wait for Lily.

There was a special trick to opening the storeroom door; Lily had showed him the last time they were there. Being one of the professor's favourite pupils, Lily had been entrusted with helping him prepare ingredients, so she knew about the trick fourth bolt that needed easing off slowly otherwise it started squawking. Opening the first three bolts, James crouched on the ground and, with both hands, carefully slid the bolt out of its groove.

With a creak, the door swung open, propelling James forward onto the floor. The room was dark, but somewhere he could see the faint Lumos light of a wand. "Lily?" he murmured hopefully as he looked around him and came face to face with ... "Oh, no, you're not ...AGHH!"

James reeled as a hex struck him full in the face. Just before he crashed to the floor, he reached out and grabbed his attacker. He felt something break in his hands before he landed unconscious in a heap by the workbench.


	2. Chapter 2

"Miss Evans, what are you doing down here?"

Lily started guiltily, and then plastered a smile on her face. "Sorry, Professor Slughorn. I was ... um ... looking for you, actually. I needed to ask you something about ... uh ... flaxweed." She smiled at him. "It's for my essay, Professor, I had an idea about the effects of the flaxweed root in Pepper-Up Potion."

"To counteract the nose-steaming, I suppose," Slughorn murmured. He smiled back at Lily and placed his hand on her shoulder. "That is an excellent suggestion, but I think you'll find it would result in hives in a particularly virulent shade of blue. However ..." He paused. "Miss Evans, would you care for a goblet of mead? We could discuss this further."

"Uh ... now?" Lily glanced around the corridor, wondering where James was and hoping he was either late or already at their rendezvous spot.

"Do you have anywhere else you should be?"

"No, no, not at all," she replied faintly. At least if she were in Slughorn's study, then James would be able to escape unseen.

She followed him down the dark, winding corridor, lit only by lamplight, and past the storeroom. Professor Slughorn stopped outside the door, examining the locks. "Just one more, I think," he murmured mostly to himself, and then, remembering Lily was there, continued, "I believe you have been informed by the Headmaster about the theft of a potion from my cupboard. Euphoria may _seem_ harmless, but in the wrong hands, it can be dangerous. Fortunately, I will be able to tell who the villains are by any untoward behaviour and excessive nose-tweaking." He waved his wand in a small circle casting another Locking Charm on the door. "It won't do any harm to cast another deterrent, though, eh, Miss Evans?"

"None at all," she replied, and smiled sweetly at him. She looked back once as they were walking and that was just before she entered the professor's study. James was nowhere to be seen.

"Where is this new girl, then?" Lily demanded when she got back to the dorm. She was feeling grumpy. Slughorn had not stopped talking and she hadn't seen James anywhere. She knew he wanted their relationship to be more open, but having spent the best part of two years telling her friends that he was a dick, the thought of admitting that they were right and Potter was actually a great guy (and a fantastic kisser) made her cringe. There was also a small part of her that thought as soon as their relationship became public knowledge, James would dump her – probably in front of everyone – because she'd never been exactly _private_ about her feelings for him.

She didn't want him to dump her. It scared her how much she dreaded that happening; it had never occurred to her that she'd actually like being with him so much.

"She's changed her mind," Mary replied, sounding grouchy. "Decided she wanted to be with the Ravenclaws instead. Ugh! Margot Loveday is going to be unbearably smug having her staying with them. It's just not fair!"

Lily stared at Mary, whose petulant expression was shared by Phyllida and Sonia. Surprised, because Sonia was not someone who liked sharing the limelight with similarly beautiful girls, Lily approached the three of them. "Why are you so bothered? It would have been awkward having to share. There's barely enough room for us four, especially not with all the clothes Phyllida's got, and your Quidditch gear."

"It was your mess that put her off, I bet!" Mary snapped. "She came in, was about to unpack and then spotted all your things on the bed. Honestly, Lily, you could have tidied up. You knew she was staying with us, and we've been asking you for days!"

"What mess?" Lily asked and looked at her bed. "Look, it's just a few magazines and my make-up bag. And it's MY bed. What's her problem?"

"You're just jealous!" Phyllida said scornfully. "And stop complaining. You never wanted her here in the first place."

"Uh," Lily shook her head. This was just getting silly. "What are you going on about? I've never even met this Jill person, and you're talking as if I'm her deadly enemy, or something."

"Sirius is devastated," Sonia chipped in.

"When have you ever been concerned about Sirius Black?" Lily said and started to laugh. This had to be a joke. But when the three girls turned huffily away from her, Lily lost patience. She was not going to sit here whilst they ignored her. And she wasn't going to let James sulk, either.

"Potter!" she yelled as banged on the door of his dormitory. "Let me in!"

"He's not here!" she heard Peter yell back.

"Can I wait for him?" she asked. Then she groaned. She sounded so desperate, Sirius would be sure to rag her mercilessly. "Uhm, no, it's okay. I'll catch up with him ... later."

The door opened and Sirius stood there. "He's not here," he said coldly. "We have no idea where he is. You probably got rid of him, too."

"What?" Lily groaned. "Oh, good Godric, you're not talking about that stupid exchange student as well, are you? I've never even met her!"

"You just couldn't be welcoming, could you?" Sirius replied, and then, turning his back on her, he slammed the door in her face.

"If you're in there, Potter!" Lily screamed. "Then just so you know, it's DEFINITELY over! GOT THAT?"

She was expecting a reaction from someone – anyone – but nothing happened. The door to James' dormitory remained resolutely closed.

It was after breakfast the next morning when things really kicked off. Lily's friends had seemed in better moods when they woke up, and so she'd enjoyed breakfast with them. They were joined by Remus and Peter, who'd got up early. Sirius, they said, was still snoring when they'd left.

"What about James?" Lily asked casually. "Is he still asleep?"

Peter shrugged. "No idea. Probably gone flying."

She was dying to ask what time James had got in last night. After leaving their dorm, Lily had hung around in the common room for over an hour and then taken herself off to the library wondering if he was there. But there'd been no one except Professor Fawcett, who'd glared at her when she'd entered the Restricted Section, so she'd backed out and taken the long way back to Gryffindor Tower. Surely James must have realised she'd run into someone. It wasn't the first time one of them had been delayed. Unless ...

"Where's the new girl?" she asked Mary.

Peering over Remus' head, Mary scrutinised the Ravenclaw table. "Can't see her, but it's still quite early. If we hang around, then we're sure to catch her. I'll introduce you properly."

Lily looked at Mary curiously. Her eyes seemed almost piggy when she talked about Jill, almost as if she was a three-year-old awestruck over an ice cream.

"Has James met her?" she asked Remus, with forced idleness.

"Don't think so," Remus replied. "He was telling us to shut up yesterday. Thought we were talking about her too much." He pulled a face at Peter. "What does he know?"

Again, the same look of awe, but Lily was at least cheered by the fact that according to them, James was unaffected. Staring at Remus and Peter, she wondered if she were imagining the slavering expressions on their faces as they ate their breakfast. Another odd thing, Peter was well known for having sausages every day, yet this morning he'd refused them – even shuddering at the thought. A glimmer of a memory floated in her head; it was fantastical, but maybe ... Lily shook herself. If she was right, then she needed to get to the library to confirm the suspicion. However, as she walked across the Great Hall and towards the door, she heard shouting coming from outside.

"I KNEW IT WAS YOU, POTTER!" Professor Slughorn was yelling.

"No, no, sir, please." A very red-faced James was yelping as Professor Slughorn pulled him along by his ear through the Entrance Hall.

"Professor Slughorn," called the Headmaster. He walked past Lily, making a small gesture with his hand, which she took to mean she could follow. "Professor, do you mind telling me what Mr Potter is being accused of?"

Horace Slughorn straightened himself up to his full height and let go of James. "I went to my storeroom, and found this young miscreant lying on the floor. There was a bottle of mead open. He started babbling some nonsense about being hexed and locked in. Initially, I was inclined to believe him, his face is rather blistered as you can see, but then I checked my stock and discovered -" His voice broke, a choked sob stopping him from continuing.

"Um, Professor, I'm sure James will replace the mead," Lily murmured as she stared at James. He looked awful. Puffy eyes and a bright red face, it was as if he'd had a jellyfish wrapped around his head.

Professor Slughorn softened his voice but still spoke with determination. "It is not the mead, Miss Evans. Potter has stolen my last remaining stock of Felix Felicis!"

"That is indeed a grave matter," Professor Dumbledore intoned. "Mr Potter, do you have anything to say?"

"Sir, it wasn't me, honestly. I was ... uh ... bundled in the storeroom and hit with a Stinging Jinx," James pleaded, his voice strained and thick as he struggled to speak.

"And what were you doing down there, Potter?" demanded Slughorn.

"I'm Head Boy. I was on patrol."

"In the dungeons?" Slughorn spluttered. "That is the job of my Slytherins, surely?"

"Horace, we should investigate the storeroom," said Professor Dumbledore. "If the Felix Felicis really is missing, then this could be serious. Mr Potter, you will need to accompany us. Miss Evans, I request your attendance also."

Lily nodded briskly and followed the three of them down towards the dungeons. As if frozen to the spot, the students milled around them, staring open mouthed at the scene.

James had been out cold since his assailant had hexed him. He'd only been roused when Professor Slughorn had shaken him whilst roaring in his ear, apoplectic with rage. He'd tried to explain that he'd been locked in, but by then the professor had discovered his missing Felix Felicis.

He thought about dropping back to walk with Lily, but then thought better of it. If Lily had bothered to turn up last night, then he could have been out of there before the morning. Feeling groggy and with his face still flaming, he refused to catch her eye instead staring stonily ahead as they followed the two professors.

"You locked the storeroom again after you discovered Mr Potter, I trust?" Professor Dumbledore asked as they approached the door.

"Naturally!" Professor Slughorn retorted. "I wasn't about to invite any others of Potter's ilk to run amok."

"Sir, did you search James?" Lily asked. "If he took your potion, then he'd still have it on him."

"Yes, I did," Slughorn replied witheringly. "Really, Miss Evans, I do not accuse anyone lightly."

"Then ... um ... did you find it?"

Slughorn didn't answer immediately, instead turning his attention to the door.

"Professor Slughorn," said Professor Dumbledore quietly, "Miss Evans asked you a question."

"Not the Potion," Slughorn admitted. He stopped speaking, and then with a final wave of his wand, opened the door. "However, I did find this!"

He gestured towards the room, now lit by torchlight. Peering over Slughorn's shoulder, James took in the scene.

When he'd woken up, James hadn't looked at his surroundings. Despite the Professor telling them that he'd been 'inclined to believe Potter', he'd in fact done no such thing. Slughorn's immediate response had not been to inquire if James was all right, but to bellow at him. Then he'd hauled James out of the room and proceeded to frisk him in front of the curious and smirking Slytherins who loved seeing James in trouble.

"Um, Professor, what are you showing us, exactly?" Lily asked in a soft voice.

"The goblets, Miss Evans, on the table. There are two of them, my dear. I may not have found my vial of Felix on Potter, but it is clear he was not alone! Plus half a bottle of my mead has been drunk. I rather think Potter and one of his friends – probably Black – broke in here, helped themselves to my mead and then had a quarrel. Black ran off with my Felix Felicis, leaving Potter to take all the blame."

"No!"shouted James. "Look, will someone please listen to my side of the story?"

"There are signs of a disturbance," murmured Professor Dumbledore, ignoring James as he stepped into the room. "And I can see a couple of blue beads on the floor. Almost as if Mr Potter's accomplice were female ..."

James watched Lily flush as Dumbledore peered over his spectacles at her. "Are they yours, by any chance, Miss Evans?"

"I did see Miss Evans down here last night," Professor Slughorn said in disbelief. "She said she needed to see me about a plant ingredient. But ..." He faltered, deep in thought as if he were trying to remember the sequence of events. "It did all sound a bit fishy to me. However, I invited her into my study for a glass of mead. On the way, I double-locked the storeroom door. Miss Evans could not have entered the room."

"Unless she had just left," Professor Dumbledore suggested mildly. "Perhaps -"

"No!" James exclaimed. "Lily wasn't there. Look, I haven't exactly told you all the truth."

"Indeed, Mr Potter, and what is your version of the truth?" The Headmaster sounded interrogatory now. Signalling for Lily and James to join him in the storeroom, he closed the door behind them all and then bade them to sit down.

James swallowed. Casting a quick glance at Lily, he turned his attention to the Headmaster and ignored the puffing Slughorn. "I wasn't hauled in here. I unlocked the door and disturbed someone. At first, I thought it was ... er ... actually, I didn't have a clue who it was, but then the person hexed me in the face. I dropped my wand and couldn't fight back." He looked around the room, his eyes searching the floor. "It's not here. Whoever hexed me must have taken my wand."

"Did you recognise the intruder?"

James furrowed his brow, trying to recall the events, but it was all a blur. There'd been something odd about the stranger, yet also very familiar. "The thing is, sir," he began, knowing this was going to sound strange. "I can't even remember if it was a boy or a girl. It's all so fuzzy ... " He looked at the two beads that Professor Dumbledore had placed next to the goblets. "I remember those beads, though. Before I was knocked out, I stretched out my hand and grabbed them. They must have broken." Turning his face towards Professor Slughorn, he continued, "Lily doesn't like blue, and," he smirked, "Sirius hasn't got a necklace like that, _sir."_

"And why were you in my storeroom, Potter?" demanded Professor Slughorn haughtily. "Why did you try to unlock the door?"

"Uh-" _Shit, I really haven't thought this through._ "I ... um ..."

"I thought you told me you'd heard a noise," Lily put in quickly. "Just before we got here, James was explaining things." She gave him a very withering look and then turned to Professor Dumbledore. "We were supposed to be having a meeting to discuss rotas, but he didn't turn up. I was furious at the time, but I suppose I can forgive now."

_Lily Evans, I love you,_ he thought, thanking Merlin for her quick-thinking.

Professor Dumbledore unlocked the storeroom and gestured for the pair of them to leave. "You are not _entirely_ in the clear, Mr Potter, but it does appear that you were the victim here. I would ask that if you have any more thoughts about the perpetrator, Mr Potter, then you come to see me, and not tackle this yourself. The theft of Felix Felicis is not to be taken lightly."

"I know," James muttered. Then he looked directly at Professor Slughorn. "Sir, I didn't take your potion, and I didn't drink your mead, either. I can't stand it."


End file.
